1. Technical Field
The present invention relates to positioning technologies and, particularly, to a positioning method and positioning device applied in the manufacturing process of a liquid crystal panel.
2. Description of Related Art
In the manufacturing process of the Thin Film Transistor (TFT) array substrate, in order to guarantee the quality of the TFT array substrate, the width of the signal line of the TFT array substrate has to be measured. At present, before the signal line of the array substrate is measured, a laser positioning device is generally adopted to position the TFT array substrate, so the width measure device can obtain clear pictures to improve the accuracy of the measurement is improved.
At present, when the Laser positioning device is positioning the TFT array substrate, a laser emitter of the laser positioning device emits a light beam to a predetermined to-be-positioned point on the TFT array. The light beam is then reflected by the predetermined point to form a reflected light beam and is received by a receiver of the positioning device. The positioning device determines height information of the to-be-positioned point according to the received reflected light beam, and then adjusts the height of the TFT array substrate according to the height information of the to-be-positioned point, which allows the TFT array substrate to be located at a height suitable for the measurement thereof carried out by the height thereof.
However, during the positioning, the surface of the TFT array substrate already is rough due to a number of elements formed thereon, and impurities may exist on the TFT array substrate surface. If the area of the surface corresponding to the to-be-positioned point is rough or have the impurities covered thereon, the light beam from the laser emitter will be scattered at the positioning point. In this condition, the reflected light beam may be projected to a position outside the receiving scope of the receiver. As such, the receiver cannot receive the reflected light beam from the positioning point, resulting in failure of the positioning.